Bilbo Baggins had been planning to abandon the Shire and eventually return to the Rivendell and spend the rest of his life with Elrond and the Elves. He scheduled his disappeareance as an abrupt event to concur during his birthday speech.

The party was double and also was celebrating Frodo's coming-of-age in his 33 years. Another significance was that Bilbo's and Frodo's years on that day summed up 144 - a gross, and for that reason a portion of the party was "invitation only" with 144 guests.

It was a huge and expensive celebration attended by most hobbits in the area. The party included copious amounts of food and drink, Gandalf the Grey provided fireworks for entertainment, and the presents given by Bilbo were made by the Dwarves of Erebor.

The occasion was notable in Hobbiton for Bilbo's abrupt disappearance (he used the Ring to disappear at the end of his speech). Bilbo then passed behind the surprised guests and returned to Bag End where Gandalf was waiting for him, and persuaded Bilbo to leave the Ring in Frodo's keeping when he departed.